The present invention relates to animation technology generally and more particularly to the animation of feathers and related surface-attached elements.
Media productions have employed increasingly complex animations in order to construct increasingly realistic images. In addition to animating surfaces, increasing attention has been directed towards surface-attached elements including feathers, hair, and fur. (U.S. Pat. App. 2003/0179203; U.S. Pat. No. 6,720,962; U.S. Pat. No. 6,952,218)
Feathers, in particular, have been a challenging subject since the early days of animation. Birds of early animation films were often secondary characters with relatively few unrealistic feathers. Although more realistic effects have been achieved in modern animation, challenges remain especially for animating birds with a large number of feathers throughout an animation sequence. For example, when using conventional animation techniques, individual feathers are likely to intersect with one another or the skin surface so that the animation is unrealistic. In addition to these intersections (also known as interpenetrations or collisions), the layering of the feathers may be inconsistent when the frames are independently developed for an animation sequence so that feathers “pop” from frame to frame.
A number of somewhat unrealistic solutions have been tried including, for example, setting the feathers at fixed angles with sufficient spacing between feathers to avoid interpenetrations. Also, by making the coloring uniform, a certain degree of feather interpenetration can be tolerable (i.e., minimally visible). Additionally, manual intervention can be introduced to correct for the defects of automation.
Thus, there is a need for improved animation for feathers and related surface-attached elements.